In lithography processes, a resist is applied onto a processing object, and, thereafter, a heating process is performed which is for the purpose of removing the solvent in the resist, completing the photosensitive reaction of the resist after light exposure, or reducing the standing wave effect.
However, in the heating process, if dust is present on a holder that holds the processing object while heating the object, there is a risk that temperature unevenness or conveyance error would be caused. Accordingly, it is required to reduce dust on the holder.